Hi I am having a similar problem but am coming from using the ISPmail tutorial for Debian Lenny from workaround.org.
I have Dovecote, Amavis, Clamav Postfix and SpamAssassin installed
Whenever I send a test email like this:

I have experienced a similar problem to you with a Postfix Amavis and Clamav installation.I have searched the net, and cant find anyone that seems to have posted a fix.
For some reason it appears as if the clamd.ctl file is not being created, or alternatively there is some permissions that are blocking it from being made.

Having tried re-installing and removing Clamav and getting the message numerous times that the latest version is installed I would be very confidant in stating that unless there is a problem with the latest version then that is not the problem.
I have also followed the instructions about stopping and restarting Clamav and Amavis... and it is not that either.
Adding users... it does not help

Being new to Linux, it has been a learning curve getting this far relatively easily, but I having being searching for a fix for this for over a week now , and cant find any solution - this is like a Brick wall